Arctic sea ice extent hit its minimum on September 9 this year, falling to its second lowest value since satellite measurements began in 1979, according to the National Snow and Ice Data Center . More than one third (35%) of the Arctic sea ice was missing this summer, compared to the 1979 - 2000 average. This is an area about the size of the Mediterranean Sea. The 2011 sea ice minimum was very close to the all-time record low set in 2007; in fact, the University of Bremen rated the 2011 loss the greatest on record. For the fourth consecutive year, and fourth time in recorded history, ice-free navigation was possible in the Arctic along the coast of Canada (the Northwest Passage), and along the coast of Russia (the Northeast Passage.) Mariners have been attempting to sail these waters since 1497.

While the record low sea ice year of 2007 was marked by a very unusual 1-in-20 year combination of weather conditions that favored ice loss (including clearer skies, favorable wind patterns, and warm temperatures), 2011's weather patterns were much closer to average. The fact we pretty much tied the record for most sea ice loss this year despite this rather ordinary weather is a result of the fact that large amounts of thicker, multi-year ice has melted or been flushed out of the Arctic since 2007. As a result of the loss of this old, thick ice, both 2010 and now 2011 set new records for the lowest volume of sea ice in the Arctic, according the University of Washington PIOMAS model. Given the very thin ice now covering most of the Arctic, we can expect truly dramatic sea ice loss the next time 1-in-10 year or 1-in-20 year warmth and sunshine invades the Arctic. We are definitely on pace to see the Arctic virtually sea ice-free in summer by 2030, as predicted by several leading Arctic sea ice scientists. I expect we'll see more than half of the Arctic ice gone and the North Pole liquid instead of solid by the summer of 2020, and probably sooner.

When was the last time the Arctic was this ice-free?We can be sure the Northwest Passage was never open for ice-free navigation--particularly ice-free navigation for multiple years in a row--between 1900 and 2000, as we have detailed ice edge records from ships (Walsh and Chapman, 2001). It is very unlikely the Passage was open between 1497 and 1900, since this spanned a cold period in the northern latitudes known as "The Little Ice Age". Ships periodically attempted the Passage and were foiled during this period, and the native Inuit people have no historical tales of the Passage being navigable at any time in the past.

The Northwest passage may have been open multiple years in a row for ice-free navigation at some period during the Medieval Warm Period, between 1000 and 1300 AD. A better candidate was the period 6,000 - 8,500 years ago, when the Earth's orbital variations brought more sunlight to the Arctic in summer than at present. Funder and Kjaer (2007) found extensive systems of wave generated beach ridges along the North Greenland coast that suggested the Arctic Ocean was ice-free in the summer for over 1,000 years during that period. Prior to that, the next likely time was during the last inter-glacial period, 120,000 years ago. Arctic temperatures then were 2 - 3°C higher than present-day temperatures, and sea levels were 4-6 meters higher.

However, it is possible that the recent summer low-ice conditions in the Arctic are unprecedented for the past 800,000 years, according to a 2011 press release by Project CLAMER, a European group dedicated to climate change and European marine ecosystem research. They found that a tiny species of plankton called Neodenticula seminae that went extinct in the North Atlantic 800,000 years ago has become a resident of the Atlantic again, having drifted from the Pacific through the Arctic Ocean thanks to dramatically reduced polar ice. The 1999 discovery represents "the first evidence of a trans-Arctic migration in modern times" related to plankton, according to the UK-based Sir Alister Hardy Foundation for Ocean Science, whose researchers warn that "such a geographical shift could transform the biodiversity and functioning of the Arctic and North Atlantic marine ecosystems."

It is possible we'll have a better idea of historical ice-free conditions in the Arctic in the next few years. A new technique that examines organic compounds left behind in Arctic sediments by diatoms that live in sea ice give hope that a detailed record of sea ice extent extending back to the end of the Ice Age 12,000 years ago may be possible (Belt et al., 2007). The researchers are studying sediments along the Northwest Passage in hopes of being able to determine when the Passage was open during the past 12,000 years.

August 2011: Earth's 4th - 8th warmest on recordAugust 2011 was the globe's 8th warmest August on record, according to the National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center (NCDC). NASA's Goddard Institute for Space Studies rated August the 4th warmest on record. Land temperatures during August were the 2nd warmest on record, and ocean temperatures were the 12th warmest on record. Ocean temperatures in the Atlantic Ocean's Main Development Region (MDR) for hurricanes, from the coast of Africa to the coast of Central America between 10°N and 20°N latitude, were 0.8°C above average, the 4rd warmest August on record. Global satellite-measured temperatures for the lowest 8 km of the atmosphere were the 6th or 3rd warmest in the 34-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH). For more details on global extremes during August, see the details from weather historian Christopher C. Burt.

Maria hits NewfoundlandHurricane Maria hit Newfoundland, Canada yesterday afternoon near 3:30 pm local time as a Category 1 hurricane with 75 mph winds. However, the hurricane's strongest winds were over water, and the storm brought very little in the way of strong winds or heavy rain to the island. Cape Race at the southeast tip of Newfoundland saw sustained winds of 41 mph, gusting to 54 mph at 3:30 pm Friday as the center of the storm passed. Winds in the capital of St. John's peaked at 37 mph, gusting to 46 mph, at 10:30 am local time. Maria's strike makes this Newfoundland's second consecutive year with a hurricane strike, something that has never occurred since hurricane record keeping began in 1851. Last year, Hurricane Igor killed one person on Newfoundland, and damage exceeded $100 million, making Igor the most damaging tropical cyclone in Newfoundland history.

Invest 97LFor the first day since August 18, we don't have a named storm in the Atlantic. However, we have a new area to watch. A tropical wave that moved off the coast of Africa Friday and is now 300 miles south of the Cape Verde Islands is moving west at 10 - 15 mph. The wave has developed a modest amount of heavy thunderstorm activity and spin, and has been designated Invest 97L by NHC. Wind shear as diagnosed by the SHIPS model is light, 5 - 10 knots, and is predicted to stay light to moderate through Tuesday morning. Ocean temperatures are 27.5°C, one degree above the threshold typically needed for a tropical storm to spin up. Water vapor satellite images show 97L is embedded in a moist environment.

Most of the models develop 97L into a tropical depression by Tuesday; NHC gave the disturbance a 20% chance of developing into a tropical depression by Monday in their 2 pm Tropical Weather Outlook. 97L should head west or west-northwest towards the Lesser Antilles over the next six days, and could arrive in the islands as early as Friday--though most of the models predict a later arrival. It is likely 97L will encounter the usual troubles storms this year have had with wind shear and dry air on the long trek across the Atlantic.

I'll have a new post on Monday, when I'll discuss the long-range hurricane outlook for the rest of September.

Please ignore him, he's getting banned all the time and he keeps on making new and new accounts. I feel like a broken record saying it, but the person you're quoting likes attention, ie a total moron. Ignore.

"Catastrophe modeling firm AIR Worldwide has revised its industry insured loss estimates for Hurricane Irene’s impact in the Bahamas to between $200 million and $400 million (previously $300 million to $700 million)."

Quoting TropicalAnalystwx13:Also, according to local officials, Irene was the worst storm to hit the area since Floyd (1999).

Believable, I guess, mainly because Frances and Jeanne didn't do damage to the entire archipelago; mainly the NW Bahamas was impacted. However, damage to Grand Bahama and Abaco from those two storms likely rival Irene's costs, simply because they are two of the three most populated / developed islands in the country. By comparison the SE islands have less to damage.

This page displays a variety of guidance and information for LOW INVEST (AL97). Please be aware that your use of this page is governed by the UCAR Terms of Service and this site's disclaimer. The model guidance displayed in the plots on this site come from a variety of modeling centers outside of NCAR. To obtain help for any item on this page, click on the question mark beside that item.

A lot of the models like the idea of the storm moving more northerly in the short term, then turning towards the west in the long run.

This page displays a variety of guidance and information for LOW INVEST (AL97). Please be aware that your use of this page is governed by the UCAR Terms of Service and this site's disclaimer. The model guidance displayed in the plots on this site come from a variety of modeling centers outside of NCAR. To obtain help for any item on this page, click on the question mark beside that item.

I've had over an inch today as we had a nice cell just train over our neighborhood! More rain is to the west of us right now and it's thundering but that system may stay west and north of us. It's funny but 1.2 inches of rain represents about 1/12 of our entire yearly rain total so far this year (we're now over 13 inches for the year). I wouldn't be surprised if we end up with 2-4 inches over the next few days.

Well it ain't over till its over, but I think it is over at least for me. I'll hang around a few more days in Ensenada Honda then weigh anchor and head a bit West for a new location. After that I really hope it is over.

Well...I saw a post from NWS PR that discusses prolonged period of unsettled weather due to massive upper low over PR...

Pop up t-storms today over PR are associated with cold core instability of upper low...followed by the arrival of surface trough (mid to low-level reflection) of upper low currently near Lesser Antilles in coming days. That surface trough producing plenty of clouds over Antilles right now...

I was talking about the area of showers over the mid atlantic, I live in VA.

Well since there are so many areas of interest out there grabbing your attentions....decided to do a quick analysis for today....

1)Surface trough over the Bahamas...I can't say yet where the surface trough came from because I haven't analyzed my collected data for September yet. But this surface trough has support from divergence due to a cut-off upper trough to the northwest...as well as an outlfow channel streaming southeastward into the massive cut-off upper low currently over Puerto Rico....

2)Central Atlantic disturance...major cut-off upper low over Puerto Rico has triggered this...can't say yet where the upper low originated from because I haven't analyzed my collected data for September yet. But this upper low is generating a surface trough near the northern Lesser Antilles...as well as a large area of cloudiness...associated with divergence on the east side of the upper low. Pop up T-storms over Puerto Rico are under the upper low center due to cold core instability associated with the upper low.

3) Area near 35W...a surface tropical low that came off of Africa...briefly mentioned and then removed in the NHC Tropcial Weather Outlook earlier on September 14.

4) 97L...the second surface tropical low that came off of Africa this week...

If I'm not mistaken this ULL is the same one that made Maria's life difficult.

And what I bolded I believe is incorrect, the CATL disturbance is not that one, the one once mentioned was absorbed by 97L. The CATL disturbance has been sitting there for days.

PR, just some cloudiness and some light to moderate showers, been seeing a light rain from that since late this morning.

Well...I saw a post from NWS PR that discusses prolonged period of unsettled weather due to massive upper low over PR...

Pop up t-storms today over PR are associated with cold core instability of upper low...followed by the arrival of surface trough (mid to low-level reflection) of upper low currently near Lesser Antilles in coming days. That surface trough producing plenty of clouds over Antilles right now...

I've been in lurking in this blog since 2006 and I have seen much worse stuff on here. I think it was last year or the year before that some guy used to get on here and say horrible bad words and racist slangs. Not to mention JFV!!!

Funny you should mention that area as I was looking at that earlier and thought the same thing. I just dont know how to post any images. Happy that someone else saw it

Well since there are so many areas of interest out there grabbing your attentions....decided to do a quick analysis for today....

1)Surface trough over the Bahamas...I can't say yet where the surface trough came from because I haven't analyzed my collected data for September yet. But this surface trough has support from divergence due to a cut-off upper trough to the northwest...as well as an outlfow channel streaming southeastward into the massive cut-off upper low currently over Puerto Rico....

2)Central Atlantic disturance...major cut-off upper low over Puerto Rico has triggered this...can't say yet where the upper low originated from because I haven't analyzed my collected data for September yet. But this upper low is generating a surface trough near the northern Lesser Antilles...as well as a large area of cloudiness...associated with divergence on the east side of the upper low. Pop up T-storms over Puerto Rico are under the upper low center due to cold core instability associated with the upper low.

3) Area near 35W...a surface tropical low that came off of Africa...briefly mentioned and then removed in the NHC Tropcial Weather Outlook earlier on September 14.

4) 97L...the second surface tropical low that came off of Africa this week...

Quoting TropicalAnalystwx13:People aren't leaving because of the Global Warming posts, they've dealt with those for years. They are leaving because people get way too out of hand and start disrespecting one another. If you don't have anything nice to say, then don't say anything at all.

I've been in lurking in this blog since 2006 and I have seen much worse stuff on here. I think it was last year or the year before that some guy used to get on here and say horrible bad words and racist slangs. Not to mention JFV!!!